IMO,Iron is pretty much all the fertilizer you need. Chelated. I've found even the one sold at Home Depot in liquid for $11 a gallon does work. For all types of plants. A little a day keeps the yellows away.
So far its gotten some swords to just explode,mosses to deep green then ever before,Crypts to become weeds..on and on.
Iron.
So I bought 5 mosses based on some of the suggestions here. They came attached to steel mesh already. I've put them along on some gravel into a 12litre tank I bought as a quarantine tank.
I filled it with water from the main tank. I'm currently using a desk lamp to light it - I just bought a mini 20litre filter and a sponge filter, either of which can go in there but I'm wondering a few things...
If it is JUST use it for moss to grow outside of use as a quarantine tank...
1) does the moss need a filter to grow? D
2) does it need a heater to grow?
Most importantly, if I replace the water in the moss/quarantine tank with "dirty" water from my main tank each week BEFORE performing a water change on my main tank...
3) Is that good for the moss to get nutrients from the fish waste and co2? Or is it bad, especially with our a filter/oxygen.
4) Does it even need oxygen pump to grow?
Lastly, if I breed shrimp in this tank (and get another quarantine tank) and keep this for just the moss and shrimp..... Do I need any of the above? Filter, or heater? (I will put air pump for shrimp)